metadata/service/server/proxy.yml

applications:
- etcd
classes:
- service.etcd.support
parameters:
  etcd:
    server:
      enabled: true
      bind:
        host: ${_param:host_address}
      proxy: true
      members:
        - host: ${_param:cluster_node01_address}
          name: ${_param:cluster_node01_hostname}
        - host: ${_param:cluster_node02_address}
          name: ${_param:cluster_node02_hostname}          
        - host: ${_param:cluster_node03_address}
          name: ${_param:cluster_node03_hostname}